Can I configure formatting for uncontrolled builds

[RobSmyth]

Hi,

I want to make uncontrolled builds always pre-release, regardless of branch, and with the pre-release tag "Uncontrolled". Is this possible?

Here an uncontrolled build is any build not made on the build system.

Background: I want to ensure that builds made on the build system are distinct from builds made dev boxes ("uncontrolled" builds).
For reproducibility/traceability it must never be possible for an uncontrolled build to have the same version as a build off the system.

IMO reproducibility/traceability of a dev box is dubious, so best to make it clear they are "uncontrolled". e.g: Dev makes code change builds then reverts, makes different changes and rebuilds, then reverts again.

So, I'm looking for something like:

Version	Host	Description
1.2.3	Build system	Release branch NuGet package version
1.2.3-Uncontrolled	Uncontrolled	Release branch NuGet package version
1.2.3+567.7f32d0	Build system	Release branch informational version
1.2.3-Uncontrolled+U.7f32d07f32d0	Uncontrolled	Release branch informational version
1.2.3-Beta	Build system	Developer or feature branch build NuGet package version
1.2.3-Uncontrolled+U.7f32d0	Uncontrolled	Developer or feature branch build informational version

In the past I have done this programmatically in the build process but it would be better to use GitVersion in VS.
I've experimented with using {env:BUILD_NUMBER ?? Uncontrolled} for Tag but gives a compile time error.

Can this be done? No hope?